Cutter chain



May 2, 1944 f E J. DoBERsTExN 2,348,061l

CUTTER CHAIN Filed July l0, 1943 liiuinluh nlgiBiE- [NVE/vree /TroR/VEY Patented May 2, 1944 UNITED STATES PATENT OFFICE CUTTER CHAIN Application July 1i), 1943, Serial No. 494,162

(Cl. 262-33i) 8 Claims.

This invention relates to improvements in cutter chains for kerf-cutting machines of the type adapted to cut coal in mines underground and has as its principal objects to provide a novel form of means for detachably holding a cutter bit in a cutter chain block so the chain may readily be adapted for cutting in reverse directions,

Other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying l drawing wherein:

Figure 1 is a View in side elevation of a portion of a cutter chain, with certain parts of the bit carrying block shown in longitudinal section in order to illustrate certain details of my invention;

Figure 2 is a plan View ofthe bit carrying block of the cutter chain shown in Figure 1;

Figure 3 is a transverse sectional view taken substantially along line 3 3 of Figure 1;

Figure 4 is a longitudinal sectional View taken through the bit holding portion of the cutter chain block showing the bit positioned for cute ting in a direction opposite to that shown in Figure 1 and showing certain other details than in Figure 1;

Figure 5 is a fragmentary transverse sectional view taken substantially along line 5-5 of Figure 4; and.

Figure 6 is a horizontal sectional view taken through the bit holding portion of the block, showing certain details of the means for clamp-V ing the bit holder and cutter bit in positionl in the block.

The cutter chain shown in the drawing and embodying the principles of my invention may be made up of a series of chain blocks I0, IE! connected together by a series of parallel spaced straps II, II. Said chain is driven from a suitable sprocket (not shown) and is guided in a guide channel extending around a cutter bar (not shown) projecting from a kerf-cutting machine, for cutting a kerf in a coal seam as the cutter bar is sumped into the coal face and fed with respect thereto, in a manner well known to those skilled in the art.

The chain block I is provided with a project--y ing bit carrying boss I2 having a bit holder I3, carried in an apertured portion I i of said boss, extending through the center of said boss. Said bit holder is adapted to. receive and clamp a bit I5 in said block, and said bit and bit holder are held in position in said block by means of set screws I6, I6 threaded in opposite ends of said boss. A clamping chamber I is rotatably carried by each of said set screws, for engagement with opposite sides of said bit holder.

The cutter oit I5 may be of any type and is preferably of the double ended type known as the throw-away bit, made of flat bar stock, havinga substantially uniform rectangular cross section and having opposite ends thereof cut oif at an angle to denne cutting points.

The bit holder I3 is provided with a shank I9, herein shown as being circular in cross section, which fits in the apertured portion I4 of the boss i2. A head 2id is formed on the outer end of said bit holder and serves to back up and embrace opposite sides of the cutter bit I5, which is mounted in an inclined bit receiving slot 2|, formed in said bit holder and extending downwardly through said head and shank. The inner face of said slot is at an angle with respect to the longitudinal axis of said bit holder, to position the point of said bit at the proper angle for cutting, and the lower end of said slot is at an angle parallel to the lower edge of the cutting point of the bit, to form a stop, to limit inward movement of said bit.

The shank I9 of said bit holderis provided with a pair of oppositely disposed recessed portions having inclined lower faces 22 and 23 respectively. Said inclined faces 22 and 23 are adapted to be engaged by corresponding inclined faces 2l', 21 of the clamping members II, I 1, so said clamping members will move said bit holder into the block and hold said bit holder and cutter bit therein, as they are moved towards said bit holder by their respective set screws. Said clamping 3 members are each provided with a depending lug 29, which is adaptedto engage a keyway 3l] cut in the threaded aperture for the respective set screw It, to hold said clamping members from rotation during tightening or loosening of said set screws. Each clamping member is also provided with an inclined engaging face 3|, inclined its inner end engages the lower end of said bit receiving siot. The advance set screw I is then turned so that the inclined engaging face 2l of the clamping member Il comes into engagement with the inclined surface 22 of the bit holder and so that its advance engaging face 3| comes into engagement with the lower advance portion of the bit I5. vThe opposite set screw I6 is then tightened, to engage the engaging face. 21 with the inclined face 23 of said bit holder, and to move said bit holder into said boss by the wedging action obtained by rectilinearly moving the inclined surface 21A along the correspondingly inclined clamping surface 23, to firmly clamp said bit holder and the cutter bit in the bit holding boss of said cutter chain.

When it is desired to reverse the direction of cutting, it is simply necessary to back out the two set screws IB, I6 to a point where the bit may be removed from the bit holder, and turn the bit holder 180 degrees in itsv bit receiving aperture I4. The bit may then be replacedand the advance set screw I6 may then be advanced into the bit receiving boss I2 to a position so that the face 3I of its clamping member I 'I abuts the lower portion of the advance face of the bit. The opposite set screw is then turned in a direction to engage its engaging face 2'I with the engaging face 23 of the recessed portion of said bit holder, to firmly clamp said bit holder and bit in position in the block.

It may be seen from the foregoing that a simplified form of bit holder has been provided, for securely holding a detachable bit in a cutter chain, which may readily be adapted for cutting in reverse directions, and which is clamped in the chain in such a manner that it cannot be thrown from the chain block during cutting.

While I have hereinshown and described one form in which myV invention may be embodied, it will be understood that the construction thereof and the arrangement of the various parts may be altered without departing from the spirit and scope thereof. Furthermore, I do not wish to be construed as limiting my invention to the specific embodiment illustrated, excepting as it may be limited in the appended claims.

l I claim as my invention:

l. In a reversible cutter chain and in combination with 'a bit carrying chain block, a bit holder adapted to t in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to receive a cutter bit, and having a pair of oppositely disposed transversely extending recessed Vportions having engaging surfaces inclined upwardly from the outer sides thereof, and clamping means slidably mounted in said block and adapted to be moved into engagement with said inclined surfaces of said recessed portions, for clamping said bit holder and cutter bit Within said block. Y

2. In a reversible cutter chain and in combination with a bit carrying chain block, a bit holder adapted to fit in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to receive a cutter chain bit, and having a pair of oppositely disposed recessed portions having lower plane surfaces inclined upwardly from the outer sides thereof, clamping means slidably mounted within said block on opposite sides of said bit holder, and adapted to engage said inclined surfaces, for holding said bit holder and bit within said block, said clamping means in the advance portion of said block also being adapted to engage the lower portion of an advance face of the cutter bit.

3. In a reversible cutter chain and in combination with a bit carrying chain block, a bit holder adapted to t in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to embrace the sides and rear surface of a cutter bit, and having a pair of oppositely disposed transversely extending inclined engaging surfaces, a set screw threaded in each end of said block for movement towards said bit holder, and a separate clamping member projecting from the inner end of and rotatably carried by each of said set screws, each of said clamping members having an inclined face adapted to engage one of said transversely extending engaging surfaces, for moving said bit holder into said block with a wedging action and for holding said bit holder and cutter bit therein.

4. In a reversible cutter chain and in combination with a bit carrying chain block, a bit holder adapted to t in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to receive a cutter bit. and having a pair of oppositely disposed transversely extending inclined engaging surfaces, a set screw threaded in each end of said block for Vmovement towards said bit holder, and a separate clamping member projecting from the inner end of and rotatably carried by each of said set screws, each of said clamping members having an inclined face adapted to engage one of said transversely extending engaging surfaces, for moving said bit holder into said block with a wedging action and forV holding said bit holder and cutter bit therein, each of said clamping members having a surface inclined at the angle of the cutter bit, and the advance of said clamping members being adapted to engage the lower end of the cutter bit, to form an abutment therefor.

5. In a reversible cutter chain and in combination with a bit carrying chain block, a bit holder adapted to t in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to embrace the sides and rear surface of a cutter bit, and having a pair of oppositely disposed transversely extending inclined engaging surfaces, a set screw threaded in each end of said block for movement towards said bit holder, and a separate clamping member projecting from the inner end of and rotatably carried by each of said set screws, each of said clamping members having an inclined face adapted to engage one of said transversely extending surfaces, for moving said bit holder into said block with a wedging action and for holding said bit holder and cutter bit therein, and means for holding said clamping members from rotation during turning movement of said set screws.

6. In a reversible cutter chain and in combination with a bit carrying chain block, a bit holder adapted'to fit in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to embrace the sides and rear surface of a cutter bit, and having a pair of oppositely disposed transversely extending inclined engaging surfaces, a set screw threaded in each end of said block for movement towards said bit holder, and a separate clamping member projecting from the inner end of and rotatably carried by each of said set screws, each of said tion with a bit carrying chain block, a bit holder adapted to t in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to embrace 'the sides and rear surface of a cutter bit, and having a pair of oppositely disposed transversely extending recessed engaging surfaces, inclined upwardly towards the center thereof, a set screw threaded in each end of said block for movement towards said bit holder, a separate clamping member rotatably carried by each of said set screws, each of said clamping members having an inclined face adapted to engage one of said transversely extending surfaces, for moving said bit holder into said block with a wedging action and for holding said bit holder and cutter bit therein, each of said clamping members having a surface inclined at the angle of the cutter bit and the advance of said clamping members being adapted to engage the lower advance portion of the cutter bit, to form an abutment therefor, and means for holding said clamping members from rotation during turning movement of said set screws.

8. In a reversible cutter chain and in combination with a bit carrying chain block, a bit holder adapted to t in an apertured portion of said chain block, said bit holder having a forward slotted portion adapted to embrace the sides and rear surface of a cutter bit, and having a pair of oppositely disposed transversely extending recessed engaging surfaces, inclined upwardly towards the center thereof, a set screw threaded in each end of said block for movement towards said bit holder, and a separate clamping member rotatably carried by each of said set screws, each of said clamping members having an inclined face adapted to engage one of said transversely extending surfaces, for moving said bit holder into said block with a wedging action and for holding said bit holder and cutter bit therein, each of said clamping members having a surface inclined at the angle of the cutter bit and the advance of said clamping members being adapted to engage the lower advance portion of the cutter bit, to form an abutment therefor, and means for holding said clamping members from rotation during rotation of said set screws including a lug projecting from each clamping member, adapted to engage a keyway formed in said block.

EDWARD J. DOBERSTEIN. 

